Ceftolozane pharmaceutical compositions

ABSTRACT

Pharmaceutical formulations can include ceftolozane and an alkalizing agent such as L-arginine.

RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application No. 61/792,092, filed Mar. 15, 2013; U.S. Provisional Application No. 61/793,007, filed Mar. 15, 2013; U.S. Provisional Application No. 61/882,936, filed Sep. 26, 2013; and U.S. Provisional Application No. 61/893,436, filed Oct. 21, 2013. The contents of these applications are incorporated hereby by reference in their entireties.

TECHNICAL FIELD

This disclosure relates to pharmaceutical compositions comprising ceftolozane.

BACKGROUND

Ceftolozane is a cephalosporin antibacterial agent. The antibacterial activity of ceftolozane is believed to result from its interaction with penicillin binding proteins (PBPs) to inhibit the biosynthesis of the bacterial cell wall which acts to stop bacterial replication. Ceftolozane is commonly combined (e.g., mixed) with a β-lactamase inhibitor (“BLI”), such as tazobactam. Tazobactam is a BLI against Class A and some Class Cβ-lactamases, with well-established in vitro and in vivo efficacy in combination with active β-lactam antibiotics.

Ceftolozane is commonly administered intravenously as a pharmaceutically acceptable salt, most commonly as ceftolozane sulfate (I):

Intravenous administration imposes a number of stringent requirements on a pharmaceutical composition. The drug is typically provided as a lyophilized product that is reconstituted immediately prior to use. However, patients receiving intravenous medication are at risk for developing phlebitis, which is an inflammation of the veins. To reduce the likelihood of the patient developing phlebitis, the reconstituted pharmaceutical composition should have a pH above 5.9 and preferably at least 6.3, and the osmolarity should be less than 600 mOsm/L (see for example, Stranz and Kastango, International Journal of Pharmaceutical Compounding 6:216 2002). Achieving a suitable pharmaceutical composition is further complicated by the fact that decomposition products are formed from ceftolozane during lyophilization and thereafter during storage (see Examples 5-7). Achieving a suitable pharmaceutical composition is further complicated by the fact that alkalizing agents used bring the pH of the reconstituted pharmaceutical composition into the correct pH range, also cause decomposition products during lyophilization and storage (see Examples 3 and 4).

Accordingly, there is a need for improved ceftolozane sulfate pharmaceutical composition with greater stability that can be reconstituted in solutions having a pH and osmolarity suitable for intravenous administration.

SUMMARY

Ceftolozane compositions can be stabilized by combination with a stabilizing-effective amount of an alkalizing agent selected from the group consisting of: sodium hydroxide, L-arginine and sodium bicarbonate. The ceftolozane compositions can be obtained by lyophilizing a solution comprising a stabilizing-effective amount of the alkalizing agent (e.g., to provide a pH of about 5-7) prior to lyophilization. The ceftolozane in the ceftolozane compositions can be ceftolozane sulfate.

It has now been found that the formation of ceftolzoane related substances (e.g., decomposition products from ceftolozane during lyophilization and subsequent storage) can be substantially suppressed when L-arginine is used as an alkalizing agent (see Examples 3 and 4). Based on these discoveries, pharmaceutical formulations suitable for parenteral administration, such as intravenous administration, are disclosed herein.

One embodiment of the invention is a pharmaceutical formulation for parenteral administration, comprising ceftolozane and between 500-700 mg of L-arginine per 1,000 mg of ceftolozane active reconstituted in 10 mL per 1000 mg ceftolozane active of a first liquid medium suitable for parenteral administration. The pharmaceutical formulation is typically diluted 10:1 v/v with a second liquid medium. The first and second liquid mediums are independently selected from sterile water, 0.9% Sodium Chloride Injection USP and 5% Dextrose Injection USP. The second medium is commonly 0.9% Sodium Chloride Injection USP.

Another embodiment of the invention is a method of treating a bacterial infection in a mammal. The method comprises intravenously administering to said mammal a therapeutically effective amount of the disclosed pharmaceutical formulation. The disclosed pharmaceutical formulation is commonly administered over one hour three times daily.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram of a lyophilization process.

FIG. 2 is a table (Table 1a) showing the effect of various alkalizing agents on the recovery of ceftolozane after lyophilization and storage.

FIGS. 3 is a table (Table 2) showing the effect of sodium bicarbonate and L-Arginine on total impurities lyophilization of pH profile.

FIG. 4 is a table (Table 3) showing the composition of various ceftolozane pharmaceutical compositions in which the sodium chloride concentration is varied.

FIG. 5 is a table (Table 4) showing data obtained by HPLC for the RT 63 impurity as detected in certain pharmaceutical compositions containing ceftolozane.

FIG. 6 is a table (Table 5) showing the composition of various additional ceftolozane pharmaceutical compositions.

FIG. 7 is a table (Table 6) showing the total purity of ceftolozane in the pharmaceutical compositions of FIG. 6, as measured by HPLC peak area.

FIG. 8 is a graph showing the total purity of certain pharmaceutical compositions disclosed in FIG. 6, as measured by HPLC peak area.

FIG. 9A is a table (Table 7) showing the amount of material from characteristic peak 1 in the pharmaceutical compositions of FIG. 6, as measured by HPLC peak area according to the analytical method as described in Example 2.

FIG. 9B is a graph showing the amount of material from characteristic peak 1 in the pharmaceutical compositions of FIG. 6, as measured by HPLC peak area according to the analytical method as described in Example 2.

FIG. 10A is a table (Table 8) showing the amount of material from characteristic peak 3 in the pharmaceutical compositions of FIG. 6, as measured by HPLC peak area according to the analytical method as described in Example 2.

FIG. 10B is a graph showing the amount of material from characteristic peak 3 in the pharmaceutical compositions of FIG. 6, as measured by HPLC peak area according to the analytical method as described in Example 2.

FIG. 11A is a table (Table 9) showing the amount of material from characteristic peak 7 in the pharmaceutical compositions of FIG. 6, as measured by HPLC peak area according to the analytical method as described in Example 2.

FIG. 11B is a graph showing the amount of material from characteristic peak 7 in the pharmaceutical compositions of FIG. 6, as measured by HPLC peak area according to the analytical method as described in Example 2.

FIG. 12 is a table (Table 10) showing the composition of various ceftolozane pharmaceutical compositions in which the sodium chloride concentration is varied.

FIG. 13 is a table (Table 11) showing the purity of Ceftolozane in CXA-201 Compositions with varying amounts of sodium from sodium chloride at time zero, 1 day, 3 days and 7 days at 60° C.

FIG. 14 is a table (Table 12) showing the HPLC area of Impurity of Peak 1 in CXA-201 Compositions with varying amounts of sodium from sodium chloride at time zero, 1 day, 3 days and 7 days at 60° C.

FIG. 15 is a table (Table 13) showing the HPLC area of the Impurity at RRT 0.43 and Impurity Peak 3 in CXA-201 Compositions with varying amounts of sodium from sodium chloride at time zero, 1 day, 3 days and 7 days at 60° C.

FIG. 16 is a table (Table 14) showing the HPLC area of Impurity of Peak 7 in CXA-201 Compositions with varying amounts of sodium from sodium chloride at time zero, 1 day, 3 days and 7 days at 60° C.

DETAILED DESCRIPTION

Surprisingly, lyophilizing ceftolozane from solutions containing certain alkalizing agents such as L-arginine, sodium hydroxide and sodium bicarbonate results in lyophilized compositions having improved ceftolozane chemical stability over the course of time and/or in the presence of heat (e.g., see Examples 3 and 4). Preferably, L-arginine can be used as the alkalizing agent to prepare pharmaceutical formulations of ceftolozane for parenteral administration. Lyophilizing a solution containing ceftolozane and an amount of L-arginine effective to adjust the pH of the solution within a desired range (e.g., pH 5-7, more preferably 6-7) can result in lyophilized compositions with improved ceftolozane chemical stability, as disclosed herein (e.g., about 600 mg L-arginine per 1,000 mg of ceftolozane active in the solution). Without being bound by theory, it is believed that L-arginine may stabilize the ceftolozane molecule during the lyophilization process, resulting in greater ceftolozane stability in the resulting lyophilized powder composition. The lyophilized stabilized ceftolozane compositions can be reconstituted to form injectable formulations having pH values within acceptable limits for intravenous administration (e.g., 6.0 and 7.0).

In one embodiment, ceftolozane can be stabilized by including a stabilizing-effective amount of L-arginine in a solution and then lyophilizing the composition. The stabilizing-effective amount of L-arginine can be an amount effective to bring the pH of the solution to 5-7, and preferably 6-7. In certain stabilized ceftolozane compositions, the stabilizing-effective amount of L-arginine 500-700 mg of L-arginine per 1000 mg ceftolozane active are used, more specifically between 575 and 625 mg and preferably about 600 mg of L-arginine per 1,000 mg of ceftolozane active in the solution. The addition of sodium chloride, preferably between 450-500 mg per 1000 mg ceftolozane active, to the solution prior to lyophilization can further stabilize ceftolozane in the resulting lyophilized product. The resulting lyophilized composition can be readily reconstituted in sterile water, 0.9% Sodium Chloride Injection USP and/or 5% Dextrose Injection USP to result in a solution having a pH (e.g., between 6 and 7) and osmolarity (e.g., about 400-600 mOsm/mL, preferably about 400 mOsm/L) that is suitable for intravenous administration.

In another embodiment, pharmaceutical compositions comprise stabilized ceftolozane sulfate and about 500-700 mg of L-arginine (preferably, about 600 mg of L-arginine) per 1000 mg of ceftolozane active. In addition, the pharmaceutical compositions can comprise about 125-500 mg (preferably between 450-500 mg) sodium chloride per 1000 mg of ceftolozane active.

Compositions comprising stabilizing effective amounts of L-arginine and/or sodium chloride provided improved ceftolozane stability over the course of time and/or in the presence of heat, and a reduction in the formation (or rate of formation) of ceftolozane-related impurities than comparative pharmaceutical compositions. Ceftolozane was less stable in compositions having less than a stabilizing effective amount of sodium chloride or in the presence of certain comparative alkalizing agents (e.g., see Examples). Preferably, stabilized ceftolozane compositions include 450-500 mg sodium chloride per 1000 mg ceftolozane active, and more specifically between 480 and 500 mg. Alternatively, ceftolozane stability can be improved in compositions comprising between about 450-500 mg sodium chloride and between about 500-700 mg L-Arginine per 1000 mg ceftolozane active in the composition, including compositions having between 480 and 500 mg of sodium chloride and 575-625 mg L-Arginine per 1000 mg ceftolozane active.

Pharmaceutical compositions can be solid powders that can be dissolved in a pharmaceutically acceptable carrier and subsequently parenterally administered to a patient. Examples of suitable pharmaceutically acceptable carriers for intravenous administration of compositions comprising stabilized ceftolozane sulfate and L-arginine include (without limitation): Sodium Chloride Injection, USP 0.9% and 0.45%, as a sterile, nonpyrogenic, isotonic solution; water for injection; and/or 0.5% Dextrose Injection, USP solution as sterile and nonpyrogenic parenteral solution containing dextrose in water for injection prepared for intravenous administration (each 100 mL of 5% Dextrose Injection, USP, contains dextrose, hydrous 5 g in water for injection).

Ceftolozane is the cephalosporin (6R,7R)-3-[(5-amino-4-{](2-aminoethyl)carbamoyl]amino]-1-methyl-1H-pyrazol-2-ium-2-yl)methyl]-7-({(2Z)-2-(5-amino-1,2,4-thiadiazol-3-yl)-2-[(1-carboxy-l-methylethoxy)imino]acetyl}amino)-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylate, and is also referred to as “CXA-101,” FR264205, or (6R,7R)-3-[5-Amino-4-[3-(2-aminoethyl)ureido]-1-methyl-1H-pyrazol-2-ium-2-ylmethyl]-7-[2-(5-amino-1,2,4-thiadiazol-3-yl)-2-[(Z)-1-carboxy-1-methylethoxyimino]acetamido]-3-cephem-4-carboxylic acid). “Ceftolozane” includes both ceftolozane free base and salts of ceftolozane, such as ceftolozane sulfate. Ceftolozane sulfate is a pharmaceutically acceptable salt of ceftolozane that can be combined with sodium chloride and other components to obtain an antibiotic composition suitable for administration by injection or infusion.

The disclosed pharmaceutical compositions can include a β-lactamase inhibitor, such as tazobactam (CAS#: 89786-04-9), avibactam (CAS#1192500-31-4), Sulbactam (CAS#68373-14-8) and/or clavulanate (CAS#58001-44-8). The beta lactamase inhibitor can be included in a crystalline or amorpous form, such as a lyophilized tazobactam or crystalline tazobactam (e.g., U.S. Pat. Nos. 8,476,425 and 5,763,603) to obtain the pharmaceutical composition. Tazobactam is the most commonly used BLI in the disclosed pharmaceutical formulations. It is typically used as the free acid, sodium salt or arginine salt. Tazobactam free acid has the following structure:

The disclosed pharmaceutical formulations preferably have a 2:1 w/w ratio of ceftolozane active to tazobactam active. A unit dosage form of the disclosed pharmaceutical formulation typically as 1000 mg of ceftolozane active, preferably from ceftolozane sulfate and 500 mg of tazobactam active, preferably from tazobactam free acid, sodium salt or arginine salt.

As used herein, “1,000 mg of ceftolozane as ceftolozane active” refers to an amount of ceftolozane sulfate effective to provide 1,000 mg of ceftolozane active. The amount of sodium chloride per gram of ceftolozane activity in a pharmaceutical composition containing ceftolozane sulfate and sodium chloride can be calculated using the relevant molecular weights of ceftolozane, ceftolozane sulfate, sodium chloride and sodium.

As used herein, “500 mg of tazobactam as tazobactam active” refers to an amount of tazobatam sodium or tazbactam arginine effective to provide 500 mg of tazobactam active.

Citric acid is a common additive to the disclosed pharmaceutical formulations. 20-22 mg of citric acid per 1000 mg ceftolozane active can be added to a stabilized ceftolozane, preferably 21 mg of citric acid per 1000 mg ceftolozane active.

Pharmaceutical compositions comprising ceftolozane and sodium chloride can be obtained by lyophilization. As is known to those skilled in the art, lyophilization is a process of freeze-drying in which water is sublimed from a frozen solution of one or more solutes. Specific methods of lyophilization are described in Remington's Pharmaceutical Sciences, Chapter 84, page 1565, Eighteenth Edition, A. R. Gennaro, (Mack Publishing Co., Easton, Pa., 1990). A pharmaceutical composition comprising ceftolozane can be prepared by adding i) L-arginine; or ii) L-arginine and sodium chloride in a fixed ratio to ceftolozane in an aqueous solution prior to lyophilization. For example, the method can comprise the steps of: (1) adding i) L-arginine or ii) L-arginine and sodium chloride and optionally citric acid to ceftolozane followed by lyophilizing ceftolozane; and (2) combining the separately lyophilized ceftolozane with other components to obtain said pharmaceutical composition. “Other components” include a BLI such tazobactam, preferably a lyophilized tazobactam. In yet a further embodiment, the method comprises adding 500-700 L-arginine and 450-500 mg sodium chloride (and optionally 20-22 mg citric acid) per 1000 mg of ceftolozane (such as the ceftolozane sulfate) in an aqueous solution, then lyophilizing the solution to obtain a lyophilized material comprising i) L-arginine, or ii) L-arginine and sodium chloride (and optionally citric acid) and ceftolozane (such as ceftolozane sulfate) in a ratio effective to stabilize the ceftolozane. The lyophilised product can then be combined with tazobactam, preferably a lyophilized tazobactam. This lyophilized product can be combined or blended with tazobactam, typically a lyophilized tazobactam. Alternatively, 550-650 mg L-arginine, 480-500 mg sodium chloride and optionally 20-22 mg citric acid per 1000 mg ceftolozane active are used. The combined products are then transferred to a vial in unit dosage form, which contains 500 mg of tazobactam active and 1000 mg ceftolozane active.

A pharmaceutical formulation for parenteral administration can include: ceftolozane and between 500-700 mg of L-arginine per 1,000 mg of ceftolozane active reconstituted in 10 mL of a first liquid medium suitable for parenteral administration per 1000 mg ceftolozane active. The pharmaceutical formulation can further comprise between 450-500 mg sodium chloride per 1,000 mg of ceftolozane active, and/or 500 mg of tazobactam active per 1,000 mg ceftolozane. The pharmaceutical formulation can be obtained wherein the ceftolozane, sodium chloride and L-arginine are co-lyophilsed and the tazobactam is separately lyophilized and combined with the ceftolozane, L-arginine and sodium chloride. The pharmaceutical formulation of can include between 575 and 625 mg of L-arginine per 1,000 mg of ceftolozane. The ceftolozane in the pharmaceutical composition is preferably ceftolozane sulfate and the tazobactam is preferably tazobactam sodium. The pharmaceutical formulation can further comprise between 20-22 mg of citric acid per 1000 mg ceftolozane. The first liquid medium can be selected from sterile water, 0.9% Sodium Chloride Injection USP and/or 5% Dextrose Injection USP. The pharmaceutical formulation is diluted 10:1 v/v with a second liquid medium selected from sterile water, 0.9% Sodium Chloride Injection USP and 5% Dextrose Injection USP. The pH of the pharmaceutical formulation can be between 5-7, preferably 6-7; and the osmolarity of the pharmaceutical formulation is between 450-550 mOsm/kg. The pharmaceutical formulation can include 1000 mg ceftolozane active.

The pharmaceutical composition can be provided in a unit dosage form comprising the pharmaceutical composition in dry form stored in a container (e.g., bag, vial, or the like) until use. Immediately prior to use, the combined unit dose is reconstituted in 10 mL of a diluent (e.g., sterile water for injection, 0.9% Sodium Chloride Injection USP and/or 5% Dextrose Injection USP). The reconstituted mixture is then diluted with 100 mL sterile water for injection, 0.9% Sodium Chloride Injection USP and/or 5% Dextrose Injection USP, after which it is ready for administration, such as by intravenous infusion.

A pharmaceutical composition can comprise ceftolozane obtained by a process comprising lyophilizing a solution including ceftolozane and an alkalizing agent selected from the group consisting of: sodium hydroxide, L-arginine and sodium bicarbonate in an amount effective to provide a pH of 5-7, preferably 6-7, to the solution prior to lyophilization to obtain a lyophilized ceftolozane pharmaceutical composition. The lyophilized ceftolozane pharmaceutical composition can comprise at least about 93% of an initial amount of ceftolozane prior to lyophilization after 3 days at 70 degrees C. after lyophilization, as measured by high performance liquid chromatography using a Develosil column ODS-UG-S; 5 micrometers; 250×4.6 mm, a mobile phase of sodium perchlorate buffer solution (pH 2.5)/CH₃CN 90:10 (v/v) at a 1.0 mL/min flow rate and oven temperature of 45° C. The lyophilized ceftolozane pharmaceutical composition can contain 1,000 mg of ceftolozane active. The alkalizing agent can be selected from the group consisting of: L-arginine and sodium bicarbonate. The lyophilized ceftolozane can be obtained by a process comprising lyophilizing a solution comprising ceftolozane sulfate, 125 mg-500 mg sodium chloride and the alkalizing agent. The lyophilized ceftolozane can be obtained by a process comprising lyophilizing a composition comprising about 1,000 mg of ceftolozane active per unit dose form in the pharmaceutical composition. The lyophilized ceftolozane can be obtained by a process comprising lyophilizing a composition comprising about 500-700 mg of L-arginine per 1,000 mg of ceftolozane active. The alkalizing agent can be L-arginine. The lyophilized ceftolozane can be obtained by a process comprising lyophilizing a solution comprising ceftolozane sulfate, citric acid, about 600 mg L-arginine per 1,000 mg of ceftolozane active, and about 125-500 mg of sodium chloride per 1,000 mg of ceftolozane active.

A pharmaceutical composition can comprise ceftolozane and an alkalizing agent selected from the group consisting of: L-arginine and sodium bicarbonate, wherein the lyophilized ceftolozane pharmaceutical composition comprises at least about 93% of an initial amount of ceftolozane prior to lyophilization after 3 days at 70 degrees C. after lyophilization, as measured by high performance liquid chromatography using a Develosil column ODS-UG-5; 5 micrometers; 250×4.6 mm, a mobile phase of sodium perchlorate buffer solution (pH 2.5)/CH₃CN 90:10 (v/v) at a 1.0 mL/min flow rate and oven temperature of 45° C. The alkalizing agent can be L-arginine. The lyophilized ceftolozane pharmaceutical composition can comprise ceftolozane sulfate, citric acid, L-arginine, and about 125-500 mg of sodium chloride per 1,000 mg of ceftolozane active. The pharmaceutical composition can further comprise sodium chloride and citric acid. The lyophilized ceftolozane composition can be obtained by a process comprising lyophilizing a solution consisting of water, ceftolozane sulfate, L-arginine, sodium chloride, and citric acid. The pharmaceutical composition can be characterized by the following: the ceftolozane is present as ceftolozane sulfate; the alkalizing agent is L-arginine; and the lyophilized ceftolozane composition is obtained by a process comprising lyophilizing a solution comprising water, ceftolozane sulfate, L-arginine, sodium chloride, and citric acid; and the pharmaceutical composition further comprises tazobactam blended with the lyophilized ceftolozane. The lyophilized ceftolozane composition can be obtained by a process comprising lyophilizing a solution comprising: 125-500 mg sodium chloride per 1,000 mg ceftolozane active; an amount of L-arginine to provide a pH of about 5-7, preferably 6-7, prior to lyophilization; about 21 mg citric acid per 1,000 mg ceftolozane active; about 487 mg sodium chloride per 1,000 mg ceftolozane active. The pharmaceutical composition can comprise tazobactam sodium in an amount providing about 500 mg tazobactam active per 1,000 mg ceftolozane active.

A unit dosage form can include a pharmaceutical composition formulated for parenteral administration for the treatment of complicated intra-abdominal infections or complicated urinary tract infections. This pharmaceutical composition can comprise 1,000 mg of ceftolozane active, about 600 mg L-arginine alkalizing agent, citric acid and about 487 mg of sodium chloride, wherein the lyophilized ceftolozane pharmaceutical composition comprises at least about 93% of an initial amount of ceftolozane prior to lyophilization after 3 days at 70 degrees C. after lyophilization, as measured by high performance liquid chromatography using a Develosil column ODS-UG-5; 5 micrometers; 250×4.6 mm, a mobile phase of sodium perchlorate buffer solution (pH 2.5)/CH₃CN 90:10 (v/v) at a 1.0 mL/min flow rate and oven temperature of 45° C. The unit dosage form can also comprise tazobactam sodium in an amount providing about 500 mg tazobactam active per 1,000 mg ceftolozane active. The unit dosage form pharmaceutical composition can be obtained by: (a) lyophilizing a ceftolozane solution comprising: about 487 mg sodium chloride per 1,000 mg ceftolozane active; an amount of L-arginine to provide a pH of about 5-7, preferably 6-7, in the solution prior to lyophilization; about 21 mg citric acid per 1,000 mg ceftolozane active, to obtain a lyophilized ceftolozane composition; and (b) blending the lyophilized ceftolozane composition with tazobactam sodium in an amount providing about 500 mg of tazobactam acid equivalent per 1,000 mg ceftolozane active in the vial.

In one aspect, provided herein is a method for the treatment of bacterial infections in a mammal, comprising administering to said mammal a therapeutically effective amount of a pharmaceutical composition prepared according to the methods described herein. A method for the treatment of bacterial infections in a mammal can comprise administering to said mammal a therapeutically effective amount of a pharmaceutical composition comprising ceftolozane sulfate and sodium chloride. Non-limiting examples of bacterial infections that can be treated by the methods of the invention include infections caused by: aerobic and facultative gram-positive microorganisms (e.g., Staphylococcus aureus, Enterococcus faecalis, Staphylococcus epidermidis, Streptococcus agalactiae, Streptococcus pneumonia, Streptococcus pyogenes, Viridans group streptococci), aerobic and facultative gram-negative microorganisms (e.g., Acinetobacter baumanii, Escherichia coli, Haemophilus influenza, Klebsiella pneumonia, Pseudomonas aeruginosa, Citrobacter koseri, Moraxella catarrhalis, Morganella morganii, Neisseria gonorrhoeae, Proteus mirabilis, Proteus vulgaris, Serratia marcescens, Providencia stuartii, Providencia rettgeri, Salmonella enterica), gram-positive anaerobes (Clostridium perfringens), and gram-negative anaerobes (e.g., Bacteroides fragilis group (e.g., B. fragilis, B. ovatus, B. thetaiotaomicron, and B. vulgates), Bacteroides distasonis, Prevotella melaninogenica). In certain embodiments of the methods described herein, bacterial infection is associated with one or more of the following conditions: complicated intra-abdominal infections, complicated urinary tract infections (cUTIs) and pneumonia (e.g., community-acquired, or nosocomial pneumonia). Community-acquired pneumonia (moderate severity only) can include infections caused by piperacillin-resistant, beta-lactamase producing strains of Haemophilus influenza. Nosocomial pneumonia (moderate to severe) caused by piperacillin-resistant, beta-lactamase producing strains of Staphylococcus aureus and by Acinetobacter baumanii, Haemophilus influenzae, Klebsiella pneumoniae, and Pseudomonas aeruginosa.

A method of treating a bacterial infection in a mammal, can include intravenously administering to a mammal a therapeutically effective amount of the pharmaceutical formulation disclosed herein (e.g., the pharmaceutical formulation is administered over one hour three times daily). The method of treating can further include reconstituting a unit dosage form of a pharmaceutical composition disclosed herein to obtain a reconstituted composition, combining the reconstituted composition with a pharmaceutically acceptable carrier and intravenously administering the unit dosage form of the pharmaceutical composition over a therapeutically effective period (e.g., 1 hour).

As used herein, “treating,” “treat,” or “treatment” describes the management and care of a patient for the purpose of combating a disease, condition, or disorder and includes the administration of a pharmaceutical composition of the present invention to alleviate the symptoms or complications of a disease, condition or disorder, or to eliminate the disease, condition or disorder. The term “treat” can also include treatment of a cell in vitro or an animal model.

By a “therapeutically effective amount” of a compound of the invention is meant a sufficient amount of the compound to treat the disorder (e.g., bacterial infection). The specific therapeutically effective amount that is required for the treatment of any particular patient or organism (e.g., a mammal) will depend upon a variety of factors including the disorder being treated and the severity of the disorder; the activity of the specific compound or composition employed; the specific composition employed; the age, body weight, general health, sex and diet of the patient; the time of administration, route of administration, and rate of excretion of the specific compound employed; the duration of the treatment; drugs used in combination or coincidental with the specific compound employed; and like factors well known in the medical arts (see, for example, Goodman and Gilman's, “The Pharmacological Basis of Therapeutics”, Tenth Edition, A. Gilman, J. Hardman and L. Limbird, eds., McGraw-Hill Press, 155-173, 2001, which is incorporated herein by reference in its entirety). The therapeutically effective amount for a given situation can be readily determined by routine experimentation and is within the skill and judgment of the ordinary clinician.

As used herein, “450-500 mg sodium chloride per 1000 mg of ceftolozane” refers to a ratio of sodium chloride to ceftolozane. For example, “450-500 to 1000 mg sodium chloride per 1000 mg of ceftolozane” includes, for example, 225-250 mg sodium chloride per 500 mg of ceftolozane, as well as, for example, 112.5-125 mg sodium chloride per 250 mg ceftolozane. In addition, “1,000 mg of ceftolozane as ceftolozane sulfate” refers to an amount of ceftolozane sulfate effective to provide 1,000 mg of ceftolozane. The amount of sodium per gram of ceftolozane activity in a pharmaceutical composition containing ceftolozane sulfate and sodium chloride can be calculated using the relevant molecular weights of ceftolozane, ceftolozane sulfate, sodium chloride and sodium.

Unless otherwise indicated, as used herein, the term “related substances” with respect to HPLC detection refers to all the ceftolozane related process impurities and degradation products other than ceftolozane separated and detected by HPLC according to Example 2. Unless otherwise indicated, as used herein, the term “% related substances” refers to the % of the total HPLC peak area obtained by Example 2 attributed to all the ceftolozane related process impurities and degradation products other than ceftolozane.

Unless otherwise indicated, as used herein, the term “ceftolozane recovery” refers to the % of total HPLC peak area obtained and detected by the HPLC method of Example 2 attributed to the amount of ceftolozane.

ILLUSTRATIVE EXAMPLES OF SELECTED EMBODIMENTS OF THE INVENTION Example 1 Manufacturing Procedure of Bulk (Tray) Lyophilized Ceftolozane

There are four main steps in the manufacture of CXA-101 bulk drug product: dissolution, sterile filtration, bulk lyophilization, and packaging into Sterbags®. These four main steps are composed of a total of 20 minor steps. The CXA-101 bulk drug product manufacturing process is presented below.

I. Dissolution

1. The prescribed amount of WFI is charged into the dissolution reactor.

2. A prescribed amount of citric acid is added.

3. The solution is cooled at 5° C. to 10° C.

4. A prescribed amount of CXA-101 drug substance is added to the solution.

5. A prescribed amount of L-arginine is slowly added to the solution.

6. A check for complete dissolution is performed. Solution pH is verified to be in the target range of 6.5 to 7.0.

7. A prescribed amount of sodium chloride is added to the solution.

8. A check for complete dissolution is performed. Solution pH is verified to be in the target range of 6.0 to 7.0. If the pH is out of this range adjust with either L-Arginine or citric acid.

9. WFI is added to bring the net weight to 124.4 kg and the solution is mixed well.

10. Samples are withdrawn for testing of final pH.

II. Sterile Filtration

11. The solution is passed through the filter (pore size 0.45 μm) followed by double filters (pore size 0.22 μm) onto a shelf on the Criofarma lyophilizer.

12. The line is washed with WFI.

13. The washing solution is passed from Step 12 through sterile filtration.

III. Bulk Lyophilization

14. The washing solution is loaded onto a separate shelf in the lyophilizer (and later discarded).

15. The solution is lyophilized until dry.

16. The product shelf is cooled to 20° C.±5° C.

IV. Packaging into Sterbags®

17. The lyophilized bulk drug product powder is milled.

18. The milled powder is sieved.

19. The sieved powder is blended for 30 minutes.

20. The powder is then discharged into Sterbags®

Prefiltration and Sterile-Filtration

Filtrate the compounded solution with a sterile tilter-set which consists of a 0.2 um polyvinylidene fluoride membrane filter (Durapore®, Millipore) and a 0.1 urn polyvinylidene fluoride membrane filter (Durapore®, Millipore) connected in tandem. Confirm the integrity of each filter before and after the filtration. Take approximately 100 mL of the filtrate in order to check bioburden.

Filter the prefiltered compounded solution through a sterile filter-set which consists of a 0.2 um polyvinylidene fluoride membrane filter and a 0.1 urn polyvinylidene fluoride membrane filter connected in tandem, and introduce the final filtrate into an aseptic room. Confirm the integrity of each filter before and after the filtration.

1.3. Processing of Vial, Stopper and Flip-Off Cap

Wash a sufficient quantity of 28 mL vials with water for injection and sterilize the washed vials by a dry-heat sterilizer. Then transfer the sterilized vials into a Grade A area located in an aseptic room.

Wash a sufficient quantity of stoppers with, water for injection. Sterilize and dry the washed stoppers by steam sterilizer. Then transfer the sterilized stoppers into a Grade A area located in an aseptic room.

Sterilize a sufficient quantity of flip-off caps by steam sterilizer. Then transfer the sterilized flip-off caps into a Grade A or B area located in an aseptic room.

Filling and Partially Stoppering

Adjust the fill weight of the filtered compounded solution to 11.37 g (corresponds to 10 mL of the compounded solution), then start filling operation. Check the filled weight in sufficient frequency and confirm it is in target range (11.37 g±1%, 11.26 to 11.43 g). When deviation from the control range (11.37 g±2%, 11.14 to 11.59 g) is occurred, re-adjust the filling weight.

Immediately after a vial is filled, partially stopper the vial with a sterilized stopper. Load the filled and partially stoppered vials onto the shelves of a lyophilizer aseptically.

Lyophilization to Crimping, Visual Inspection, Labeling and Packaging

After all filled and partially stoppered vials are loaded into a lyophilizer, start the lyophilization program shown in FIG. 1. Freeze the loaded vials at −40° C. and keep until all vials freeze. Forward the program to primary drying step (shelf temperature; −20° C., chamber pressure; 100 to 150 mTorr). Primary drying time should be determined by monitoring the product temperature. Forward the program to secondary drying step (shelf temperature; 30° C., chamber pressure; not more than 10 mTorr) after completion of the primary drying step. After all vials are dried completely, return the chamber pressure to atmospheric pressure with sterilized nitrogen. Then stopper vials completely.

Unload the lyophilized vials from the chamber and crimp with sterilized flip-off caps.

Subject all crimped vials to visual inspection and label and package all passed vials.

Example 2 Analytical HPLC Method

Unless otherwise indicated, HPLC measurements are made using a Develosil column ODS-UG-5; 5 micrometers; 250'4.6 mm, a mobile phase of sodium perchlorate buffer solution (pH 2.5)/CH₃CN 90:10 (v/v) at a 1.0 mL/min flow rate and oven temperature of 45° C. (Example 2).

A. Operative Conditions

Column Develosil ODS-UG-5; 5 μm, 250 × 4.6 mm (Nomura Chemical, Japan) Mobile phase Sodium Perchlorate Buffer Solution (PH 2.5)/CH₃CN 90:10 (vlv) Flow rate 1.0 mL/min Wavelength 254 nm Injection volume 10 μL Oven Temperature 45° C. Run Time 85 minutes

Gradient Profile:

Time (min) A % B % 0 75 25 30 70 30 60 0 100 85 0 100 85.1 75 25 110 75 25

B. Mobile Phase Preparation.

Sodium Perchlorate Buffer Solution was made by dissolving 14.05 g of sodium perchlorate Monohydrate in 1000.0 mL of water followed by adjusting pH to 2.5 with diluted perchloric acid (1 in 20).

Mobile Phase was then made by mixing Sodium Perchlorate Buffer Solution (pH 2.5) and acetonitrile in the ratio 90:10 (v/v).

Sodium Acetate Buffer Solution pH 5.5 (Diluent) was made by dissolving 1.36 g of sodium acetate trihydrate in 1000.0 mL of water followed by adjusting to pH 5.5 with diluted acetic acid (1 in 10).

C. Sample Preparation.

Sample solution: dissolve 20.0 mg, exactly weighed, of Sample, in 20.0 mL of water (Prepare just before injection into HPLC system).

System Suitability Solution (1%): take 1.0 mL of the Sample Solution (use first sample if more are present) and transfer into a 100.0 mL volumetric flask, dilute with water to volume and mix.

D. HPLC Analysis Procedure

-   1. Inject Blank (water) -   2. Inject System Suitability Solution and check for tailing factor     and theoretical plate number for CXA-101 peak:     -   The tailing factor must not be greater than 1.5     -   Theoretical plates number must not be less than 10000 -   3. Inject Sample Solution -   4. Inject System Suitability Solution and check for tailing factor     and theoretical plate number for CXA-101 peak.     -   The tailing factor must not be greater than 1.5     -   Theoretical plates number must not be less than 10000 -   5. Identify the peaks of Related Substances in the Sample     chromatogram.

E. Calculations

I. Report for each Related Substance its Amount as Expressed by Area Percent.

$C_{i} = \frac{A_{i} \times 100}{A_{t} + {\Sigma \; A_{i}}}$

wherein:

C_(i)=Amount of related substance i in the Sample, area %

A_(i)=Peak area of related substance i in the Sample chromatogram

A_(i)=Area of CXA-101 peak in the Sample chromatogram

A_(i)+ΣA_(i)=Total peaks area in the Sample chromatogram

Consider as any Unspecified Impurity, each peak in the chromatogram except CXA-101, peaks from 1 to 11 and every peak present in the blank chromatogram and report the largest.

II. Report the Total Impurities Content as Expressed by the Following Formula:

$C_{T} = \frac{A_{i} \times 100}{A_{t} + {\Sigma \; A_{i}}}$

wherein:

C_(T)=total impurities content in the Sample, area%

A_(i)=area of CXA-101 peak in the sample chromatogram

ΣA_(i)=total peak areas of impurities in the sample chromatogram

Example 3a Effects of Alkalizing Agents on Ceftolozane Recovery

A formulation close to physiologic pH was targeted. This necessitates an alkalizing agent due to intrinsic pH 1.92 of ceftolozane in solution (2%). The initial study of alkalizing agents included sodium hydroxide, L-arginine, tris, sodium bicarbonate, meglumine, diethanolamine, and triethanolamine. Samples containing 100 mg ceftolozane sulfate, 22.9 mg sodium chloride, 200 mg maltose, and 2 mg citric acid anhydrous were prepared and adjusted to about pH 4. The samples were lyophilized and powders stored at 70° C. for 3 days, 60° C. for 3, 6 and 9 days and at 40° C. for one month. The stored samples were then analyzed for ceftolozane content. Results are reported in Table 1a in FIG. 2.

Ceftolozane recovery was consistently at least 90% in the presence of sodium hydroxide, L-arginine, or sodium bicarbonate. Although sodium hydroxide performed well, as a strong base, it could promote base hydrolysis of the active more readily during scale up and be more difficult to dry during lyophilization than other alkalizing agents. Accordingly sodium hydroxide was not considered for further formulation development. Sodium bicarbonate and L-Arginine were further tested, as outlined in Example 4.

FIG. 2, Table 1a provides examples of certain preferred ceftolozane compositions that provide for a rate of ceftolozane recovery (as measured by HPLC according to Example 2) that are characterized by:

-   -   at least about 90% and more preferably at least about 93%, after         3 days at 70 degrees C.; and/or     -   at least about 95% and more preferably at least about 96%, after         6 days at 60 degrees C.; and/or     -   at least about 95% and more preferably at least about 97%, after         1 month at 75% relative humidity (RH) and 40 degrees C.

Example 3b Screening of Stabilizing Agents

The stabilizing effect of non-reducing sugars such as sucrose and trehalose, as well as polyvinylpyrrolidone (PVP), was also evaluated in a ceftolozane formulation.

Five samples were prepared, the components of which are shown in Table 1b below. Each sample contained 1000 mg of ceftolozane active, 40 mg citric acid monohydrate (equivalent of 36 mg citric acid anhydrous), and the same amount of L-arginine. Stabilizing reagents in four samples are 480 mg sodium chloride, 300 mg of trehalose, 300 mg of sucrose, and 300 mg of PVP, respectively. One sample was a control that contained no stabilizing reagent. The samples were in lyophilized form and stored at 60° C. for 7 days. The purities of the samples were monitored by HPLC on day 0, day 1, day 3 and day 7.

TABLE 1b Comparison between stabilizing reagents. Excipient NaCl Trehalose Sucrose PVP None Ceftolozane 1000 1000 1000 1000 1000 amount Excipient amount 480 300 300 300 N/A Purity: t₀ 98.42 98.09 98.14 97.89 97.94 60° C./1 d 97.85 96.73 96.97 96.05 96.15 60° C./3 d 97.21 95.36 95.81 94.57 94.53 60° C./7 d 95.65 94.21 94.19 92.78 92.06 Purity Δ (0-7 d) −2.77% −3.88% −3.95% −5.11% −5.88%

As shown in Table 1b, the sample containing sodium chloride exhibited the best stability. The purity of ceftolozane in the sample containing sodium chloride had the slightest purity drop over 7 days. This experiment further supports the discovery that sodium chloride and non-reducing sugars (e.g., sucrose, trehalose) provide a surprising stabilizing effect.

Example 4 L-Arginine Results in the Smallest Increase in Decomposition Products and the Most Stable pH Profile

A study was conducted to compare L-arginine against sodium bicarbonate. In this study, solutions were prepared to contain ceftolozane in the presence of sodium chloride and citric acid adjusted to approximately pH 6 with either L-arginine or sodium bicarbonate. The solutions were then lyophilized and samples distributed for accelerated and regular storage. A summary of the total impurities and pH for the various conditions after 1 month is presented in Table 2 in FIG. 3.

As seen in Table 2, the bicarbonate-adjusted sample showed a larger increase in related substances and a less stable pH profile. Accordingly, it was decided to maintain L-arginine as the alkalizing agent in the formulation.

Example 5 Increasing the Amount of Sodium Chloride Stabilizes Ceftolozane Pharmaceutical Compositions

Multiple stability studies were performed on ceftolozane sulfate, wherein the effect of varying amounts of sodium chloride on the stability of ceftolozane was examined.

The amount of ceftolozane in ceftolozane sulfate can be calculated based on the respective molecular molar weights of ceftolozane and ceftolozane sulfate (e.g., 1,147 mg ceftolozane sulfate contains about 1,000 mg of ceftolozane).

A. Reduction of the Impurity at RT=63 Minutes

A stability study was carried out at 25° C. as described above. High, mid, and low salt formulations contained 480, 125, and 62.5 mg NaCl per 1000 mg of ceftolozane, respectively. Compositions of blend Drug Product are listed in Table 3 in FIG. 4. Test results are summarized in the Table 4 in FIG. 5.

Conclusion: At the three month time point, the reduced salt formulations were observed to be not as stable as the full salt formulation; and trends indicate that reduction in salt causes at least 1.5-fold greater impurity at RT=63 minutes (HPLC).

B. CXA-101 Peak Trends with NaCl

A stability study was carried out at 30° C. and 60° C. as described above. Sodium chloride content in test samples is described in Table 3 (FIG. 4).

Example 6 The Amount of Sodium Chloride can be Selected to Stabilize Ceftolozane in Pharmaceutical Compositions

A 7-day stability study of multiple ceftolozane pharmaceutical compositions was carried out at 60% RH in accordance with ICH guidelines. This stability study examined the effect of temperature and humidity on various ceftolozane pharmaceutical compositions bulk drug product stability when stored in the container closure configuration of Sterbag®.

A. CXA-101 Purity increases in Compositions having at Least about 125 mg NaCl/1,000 mg Ceftolozane Active

A stability study was carried out at 30° C. and 60° C. as described in Example 6. Sodium chloride content in test samples is described in Table 5 (FIG. 6). The samples were formulated with 481, 190, 125, 75, and 50 mg sodium chloride per 1 g of ceftolozane active.

FIG. 7 is Table 6 with data for total purity of ceftolozane measured by HPLC during the 7-day stability test using the HPLC method in Example 2, with the data plotted in the graph of FIG. 8.

B. The amount of Substances identified by HPLC Peaks 1 and 7 Decreases in Compositions having at Least about 125 mg NaCl/1,000 mg Ceftolozane Active

A stability study was carried out at 30° C. and 60° C. as described in Example 6. Sodium chloride content in test samples is described in Table 5 (FIG. 6). The samples were formulated with 481, 190, 125, 75, and 50 mg sodium chloride per 1 g of ceftolozane active.

Stability data for amounts of additional substances in the ceftolozane compositions from Table 5 (FIG. 6) as measured by peaks 1, 3 and 7 by HPLC (according to Example 2) are summarized in Tables 7, 8 and 9 (FIGS. 9A, 10A and 11A). The 60° C. data are also plotted in FIGS. 9B, 10B and 11B to show trends of peak 1, RRT 0.43+peak 3, and peak 7 with respect to sodium chloride (NaCl), respectively.

Example 7 Improvement in the Purity of Ceftolozane CXA-201Pharmaceutical Compositions With Varying Amounts of Sodium Chloride

A stability study was carried out at 30° C. and 60° C. as described in Example 6. The sodium chloride content in the CXA-201 compositions is described in Table 10, FIG. 12. The HPLC data at 30° C. and 60° C. are summarized in Tables 11-14, FIGS. 13-16.

Example 8 Preferred Antibiotic Composition Comprising Ceftolozane, L-Arginine and Tazobactam

An example of the unit composition of ceftolozane/tazobactam drug product for injection is presented in Table 15 below. The composition in Table 15 can be reconstituted in water for injection or 0.9% aqueous sodium chloride to form a pharmaceutical formulation for intravenous administration for treatment of infections. The unit dosage form of Table 15 can be obtained by lyophilizing an aqueous solution comprising ceftolozane sulfate, citric acid, sodium chloride and L-arginine to obtain a lyophilized ceftolozane composition. The aqueous solution preferably contains the components of Ceftolozane composition in the Table 15, including enough L-arginate (e.g., about 600 mg per 1,000 mg of ceftolozane active in the solution) to provide a pH of about 6-7 prior to lyophliziation. The lyophilized ceftolozane composition can be combined with tazobactam (e.g., by blending a tazobactam composition comprising tazobactam sodium) in an amount providing a 2:1 weight ratio between the amount of ceftolozane active and the amount of tazobactam free acid equivalent.

TABLE 15 Unit Compositions of Ceftolozane/ Tazobactam for Injection, 1000 mg/500 mg Nominal Composition Component Function mg per Vial Ceftolozane Ceftolozane Active 1147  composition¹⁾ Sulfate Citric Acid, Chelating  21 Anhydrous Agent Sodium Stabilizing 487 Chloride Agent L-Arginine Alkalizing   600²⁾ Agent Q.S. for pH adjustment Tazobactam Sodium³⁾ Active 537 Nitrogen Processing Q.S. Aid^(i)) Total Weight 2792  ¹⁾Actual amount of ceftolozane composition will vary based on the measured potency. Ceftolozane sulfate, 1147 mg, corresponds to 1000 mg ceftolozane free base. ²⁾L-arginine is added as needed to achieve pH 6.5 ± 0.5; 600 mg per vial is considered a representative total amount. ³⁾Actual weight of tazobactam sodium will vary based on the measured potency. Tazobactam sodium 537 mg, corresponds to 500 mg tazobactam free acid 4) Nitrogen blanket is applied after powders are dispensed to the vial and prior to insertion of stopper.

The excipients in ceftolozane composition were chosen to ensure stability and processability of the ceftolozane drug substance into the drug product. The specific excipients, their quantities and functions are provided in Table 16. All excipients are compendial and typical for sterile pharmaceutical dosage forms, requiring no additional treatment prior to use in the formulation. The excipients are used in levels within the range established in other FDA approved products as described in the Inactive Ingredients Database (IID).

TABLE 16 Excipients Used in Ceftolozane Composition Inactive Concentration Ingredients Amount, in Infusion Rationale for Database Component Function mg/Vial Solution, % Inclusion (IID) Range Citric acid Chelating  21 0.02 Used to prevent 0.0025 to 50% agent discoloration and degradation Sodium Stabilizing 487 0.49 Used as a stabilizing  0.187 to 45% Chloride agent agent for ceftolozane sulfate L-arginine Alkalizing   600^(i)) 0.60 Used to adjust  0.29 to 88% agent Q.S. for pH ceftolozane solution adjustment pH ^(i))L-arginine is added as needed to achieve pH 6.5 ± 0.5; 600 mg per vial is considered a representative total amount. 

What is claimed is:
 1. A pharmaceutical composition comprising ceftolozane obtained by a process comprising lyophilizing a solution comprising ceftolozane sulfate, about 450 to 500 mg sodium chloride and L-arginine in an amount effective to provide a pH of 5-7 to the solution, and lyophilizing the solution to obtain pharmaceutical composition comprising stabilized ceftolozane.
 2. The pharmaceutical composition of claim 1, wherein the pharmaceutical composition retains at least about 93% of an initial amount of ceftolozane upon lyophilization after 3 days at 70 degrees C. post-lyophilization, as measured by high performance liquid chromatography using a Develosil column ODS-UG-5; 5 micrometers; 250×4.6 mm, a mobile phase of sodium perchlorate buffer solution (pH 2.5)/CH₃CN 90:10 (v/v) at a 1.0 mL/min flow rate and oven temperature of 45° C.
 3. The pharmaceutical composition of claim 1, wherein the lyophilized ceftolozane pharmaceutical composition contains 1,000 mg of ceftolozane active.
 4. The pharmaceutical composition of claim 1, wherein the L-arginine is present in the solution in an amount of about 500-700 mg L-arginine per 1,000 mg of ceftolozane active.
 5. The pharmaceutical composition of claim 4, wherein the solution comprises ceftolozane sulfate, about 480 mg-500 mg sodium chloride per 1,000 mg of ceftolozane active, and about 500-700 mg of L-arginine per 1,000 mg of ceftolozane active.
 6. The pharmaceutical composition of claim 4, wherein the lyophilized ceftolozane is obtained by a process comprising lyophilizing a composition comprising about 1,000 mg of ceftolozane active per unit dose form in the pharmaceutical composition.
 7. The pharmaceutical composition of claim 4, wherein the lyophilized ceftolozane is obtained by a process comprising lyophilizing a solution consisting essentially of L-arginine, ceftolozane sulfate, sodium chloride and citric acid.
 8. The pharmaceutical composition of claim 7, wherein the solution consists of water, ceftolozane sulfate, citric acid, sodium chloride and L-arginine.
 9. The pharmaceutical composition of claim 1, wherein the pharmaceutical composition comprises ceftolozane sulfate, citric acid, tazobactam sodium, about 500-700 mg L-arginine per 1,000 mg of ceftolozane active, and sodium chloride.
 10. A pharmaceutical composition comprising ceftolozane, about 450-500 mg of sodium chloride per 1,000 mg of ceftolozane active and about 500-700 mg L-arginine per 1,000 mg of ceftolozane active, wherein the pharmaceutical composition retains at least about 93% of an initial amount of ceftolozane after 3 days at 70 degrees C., as measured by high performance liquid chromatography using a Develosil column ODS-UG-5; 5 micrometers; 250×4.6 mm, a mobile phase of sodium perchlorate buffer solution (pH 2.5)/CH₃CN 90:10 (v/v) at a 1.0 mL/min flow rate and oven temperature of 45° C.
 11. The pharmaceutical composition of claim 10, wherein the pharmaceutical composition comprises tazobactam, ceftolozane sulfate, about 480-500 mg of sodium chloride per 1,000 mg of ceftolozane active, and about 600 mg L-arginine per 1,000 mg of ceftolozane active.
 12. The pharmaceutical composition of claim 10, wherein the pharmaceutical composition comprises 1,000 mg of ceftolozane active.
 13. The pharmaceutical composition of claim 10, further comprising citric acid.
 14. The pharmaceutical composition of claim 10, wherein the lyophilized ceftolozane composition is obtained by a process comprising lyophilizing a solution comprising of water, ceftolozane sulfate, L-arginine, sodium chloride, and citric acid.
 15. The pharmaceutical composition of claim 14, wherein a. the ceftolozane is present as ceftolozane sulfate; b. the L-arginine is present in an amount providing a pH in the solution of 6-7 prior to lyophilization; c. the lyophilized ceftolozane composition is obtained by a process comprising lyophilizing a solution consisting essentially of water, ceftolozane sulfate, L-arginine, sodium chloride, and citric acid; and d. the pharmaceutical composition further comprises tazobactam blended with the lyophilized ceftolozane.
 16. The pharmaceutical composition of claim 15, wherein the lyophilized ceftolozane composition is obtained by a process comprising lyophilizing a solution comprising: a. 200-500 mg sodium chloride per 1,000 mg ceftolozane active; and b. an amount of L-arginine to provide a pH of about 6-7 prior to lyophilization.
 17. The pharmaceutical composition of claim 16, wherein the pharmaceutical composition comprises tazobactam sodium in an amount providing about 500 mg tazobactam active per 1,000 mg ceftolozane active.
 18. A unit dosage form of a pharmaceutical composition formulated for parenteral administration for the treatment of complicated intra-abdominal infections or complicated urinary tract infections, the pharmaceutical composition comprising 1,000 mg of ceftolozane active, about 600 mg of L-arginine, citric acid and about 450-500 mg of sodium chloride.
 19. The unit dosage form of claim 18, further comprising tazobactam sodium in an amount providing about 500 mg tazobactam active per 1,000 mg ceftolozane active.
 20. The unit dosage form of claim 19, wherein the pharmaceutical composition is obtained by a. lyophilizing a ceftolozane solution comprising: about 487 mg sodium chloride per 1,000 mg ceftolozane active; an amount of L-arginine to provide a pH of about 6-7 in the solution prior to lyophilization; and about 21 mg citric acid per 1,000 mg ceftolozane active, to obtain a lyophilized ceftolozane composition; and b. blending the lyophilized ceftolozane composition with tazobactam sodium in an amount providing about 500 mg of tazobactam acid equivalent per 1,000 mg ceftolozane active in the unit dosage form. 